模拟草酸钚沉淀母液中草酸电解破坏研究

Electrolysis of Oxalic Acid in Simulative Mother Liquor Generated From Plutonium（Ⅳ） Oxalate Precipitation Process

摘要: 采用循环伏安法和线性扫描法对模拟草酸钚沉淀母液中草酸和钚的电化学行为进行研究。研究结果表明，HNO₃介质中的H₂C₂O₄在Pt电极上的氧化为不可逆反应。在模拟的草酸钚沉淀母液中，因Pu(Ⅳ)被C₂O^2-₄络合而未出现Pu(Ⅲ)/Pu(Ⅳ)的氧化还原峰，H₂C₂O₄的氧化峰则清晰可见，H₂C₂O₄的氧化反应仍为不可逆过程。对模拟草酸钚沉淀母液进行恒电流电解，考察了模拟母液中Pu(Ⅳ)初始浓度对草酸电解速率的影响以及电解过程中Pu价态的变化。结果表明，钚浓度为0.002～0.1 g/L时，对H₂C₂O₄的电解速率影响不大。恒电流密度下电解可将草酸钚沉淀母液中草酸的浓度破坏到0.001 mol/L以下，可满足工艺要求。

Abstract: Cyclic voltammetry and linear voltammetry methods were used to study the characteristics of electrochemical behavior of oxalic acid (OA) and plutonium at platinum anode in simulative mother liquor (OW) generated from Pu(Ⅳ) oxalate precipitation step. The cyclic voltammograms show that the oxidation of OA on Pt anode is an irreversible reaction. An electrolytic method was described for the destruction of the OA in OW. 0.002-0.1 g/L Pu has no obvious effect on the destruction velocity of OA. Under a constant current density, OA can be destroyed to below 0.001 mol/L after a certain time, which can satisfy the requirements of the technical process.